Unofficial NSA historian James Bamford, author of the essential curtain-puller Body of Secrets, provides a gripping, blow-by-blow account of the American intelligence community's ill-starred efforts to track Al Qaeda terrorists in the months leading up to September 11, 2001—and a chilling survey of what they've been up to since. Bamford's exposé does leave one key question unanswered, however: should you be more worried by the creation of the most sophisticated eavesdropping network ever conceived or the ineptitude of the people running it?

When it was first released, Privacy on the Line, by computer security legends Whitfield Diffie (of Diffie-Helman key-exchange fame) and Susan Landau, was the best guide on the market to the Crypto Wars of the '90s. The massively expanded edition published last year is the bible for anyone interested in telecom privacy, period. From the dawn of the tech to the aftermath of 9/11, this is the one volume every well-informed paranoid needs to have on the shelf.

This one's a few years old but hasn't been nearly widely enough read. Zalewski catalogs a variety of unorthodox means by which a savvy snoop might spy on computer users—from exploiting holes in the chip architectures that run encryption programs to fingerprinting a far-off machine by tracking the subtleties of IP headers. Not all of them sound especially practical, but they're all so diabolically brilliant that you'll pop a monocle every few pages.

Law prof Daniel Solove is one of the sharpest analysts on the scene today of "privacy" as construed by the courts. This incisive book takes the concept of privacy apart with impressive thoroughness, and explores how the law's impoverished understanding of privacy helps leave us all exposed.

Political scientist Robert J. Goldstein's hot-off-the-presses history tells the tortuous tale of the Attorney General's List of Subversive Organizations, and how it wrecked political groups deemed suspect by the government. Fortunately, we don't do that sort of thing anymore.